Process for the production of etched textile material containing synthetic cellulosefibers



PROCESS FOR THE PRODUCTION OF ETCHED TEXTILE MATERIAL CONTAININGSYNTHETIC CELLULOSE FIBERS Franz Hoelkeskamp, Wuppertal-Langerfeld, andHeinz Hipp, Wnppertal-Barmen, Germany, assignors to J. P. BembergAktiengesellschaft, Wuppertal-Oberbarmen, Germany No Drawing. Filed Aug.6, 1956, Ser. No. 602,446 Claims priority, application Germany Aug. 8,1955 11 Claims. (CI. 18-54) This invention relates to a process for theproduction of an etched textile material containing synthetic cellulosefibers, and more particularly to a process for the preparation andproduction of a textile material containing dyed synthetic cellulosefibers in which the dyestufl pigment is partially reduced or decomposed.

It is a familiar practice to apply suitable dyestuffs to finishedtextiles in the form of threads, yarns, cloth, fabric or the likecontaining synthetic cellulose fibers, and then etching the textilematerial in a subsequent manufacturing operation. The etching step ofthe process includes the decomposition of dystufi pigment by reactionwith a reducing agent in order to partially remove or destroy the dye atvarious locations or places on the textile material. It is also afamiliar practice to apply insoluble dyestutf pigments to a spinningsolution shortly before spinning synthetic filaments or fibers therefromin order to produce an internally dyed fiber which can be made intoultra-fast dyed textile materials.

The principal object of the present invention is to provide a processfor the production of an etched and at the same time an ultra-fast dyedtextile material containing synthetic cellulose fibers. Other objectsand advantages of the invention will become more apparent upon aconsideration of the following description of the invention.

In accordance with the invention, this principal object is achieved bydispersing a very finely divided, waterinsoluble dyestuff pigment in acellulosic spinning solution, the dyestuff pigment being capable ofbeing decomposed by a reducing agent, spinning internally dyed syntheticcellulose fibers from the spinning solution, and etching a textilematerial containing the internally dyed fibers by reaction with areducing agent.

A very fine distribution or dispersion of the dyestufi pigments in thecellulosic spinning solution is advantageously obtained by employingdyestufI pigments having a particle size of not more than five microns.spondingly, internally dyed fibers or filaments are obtained in whichthe embedded dyestuff pigments, even in the interior of the fibers, canbe etched by reaction with a reducing agent. A finely dispersed andhighly uniform suspension of the dyestuff pigmetns in the spinningsolution is further obtained by the use of a suitable emulsifying agent.Such emulsifiers are well known in the art, and only a small quantity isrequired to give a satisfactory dispersion of the water-insolublepigment.

Naturally, the dyestufi pigment selected for the process of theinvention should be resistant or inert to the prevailing operatingconditions ordinarily employed in spinning synthetic cellulose fibers.Thus, a dyestuif pigment to be dispersed in a viscouse spinning solutionshould be both alkali and acid resistant and should also be fast tosulfur compounds. Where conventional chemical treatments of the fibersand/ or textile material, such as soaping, desulfurizing and the likeare employed, the dyestutt' pigment is, of course, preferably selectedso Corre- 2,966,390 Patented Dec. 27, 1960 as to remain fast to suchtreatment. These modifications and limitations of the dyestufi employedwill be readily apparent to those skilled in the art and are mentionedherein merely as an aid in selecting suitable dyestufis' withoutdeparting from the spirit and scope of the in vention.

Examples of particular dyestuffs which are especially useful in theprocess of the invention include water-in soluble, etchable dyestuffpigments obtained as the re action products or coupling products ofnaphthols with diazotized aromatic amines, these reaction products beingcommonly classed as azoic dyestuffs. The group of Celliton dyestuffswhich are water-insoluble and also etchable or decomposable by reductionare likewise suitable for employment in the present process (e.g., seeDyestutl Tables of Schultz, 7th printing, volume 2, pages 44-45;supplemental volume 1, pages and 76; and supplemental volume 2, pages138-143).

Among the azoic dyestuffs which can be utilized as dyestuif pigments,those which have been found to be particularly advantageous include thefollowing combinations of a diazotized aromatic amine component with anaphthol component:

Fast Black Salt G, m-nitranilide of 2.3-oxynaphthoic acid;

Fast Gold Orange Salt GR, o-toluidide of 2.3-oxynaphthoic acid:

Pigment Fast (Schultz No.

Oil Red (Schultz No. 118) Oil Vermillion (Schultz No. 149) Polarorange Rconc. (Schultz No. 367) :EIIZN SlOaNa.

SOaNa Celliton dyestuff pigments which have been found to beparticularly useful in the practice of the invention include all thoseCelliton dyestufi pigments which are insoluble in water and etchablewith a reducing agent. They may be selected from the group of Cellitondyestuffs classified in Dyestuff Tables of Schultz, 7th printing, volume2, pages 1-233.

The dyestuif pigments are preferably first prepared as aqueoussuspension and this suspension then added to the spinning solution. Inorder to ensure a uniform distribution ofthe dyestuff pigments as asuspensioninan aqueous solution, thenaphthol and diazotized' amineof an"azoid dyestuff should be linked-or combined in an aqueo'us media in thepresence of an emulsifi'cation agent.- Likewise, in preparingan aqueoussuspension of a Celliton dyestuif, the dyestuif is preferably firstdissolved in alcohol after which the alcoholic solution is mixed withwater containing a suitable emulsification agent The alcohol can bevaporized so that the dyestuif pigment remains as a fine suspension inthe aqueous media. The emulsification agents employed are well known inthe artand include, for example, ethoxylated fatty alcohols orethoxylated alcoylphenols.

A suflicient quantity of the dyestuif contained in an aqueous suspensionis added to the c'ellulosic. spinning solution to give the desireddegree of coloring to the finished textile material. Generally, it ispreferred that the concentration of dyestuff pigments amount to fromabout 1% to 5%, especially about 2% to.4%, by weight of the cellulosecontent of the spinning solution.

The spinning solution containing thedispersed dyestufl. is extruded in aconventional manner into continuous filaments which can then be madeinto a textile material,

as by collecting a plurality of fibers in the form of a thread or yarnand weaving the fibers into a fabric, cloth, or the like. Internallydyed fibers or filaments are thus contained in an etchable textilematerial, i.e., a textile material containing synthetic cellulose fibersin which there has been internally incorporated a dyestuff pigmentcapable of being partially reduced or decomposed.

The etching step of the process is carried out by subjecting the textilematerial to the action of a reducing agent, preferably a strong reducingagent such as sodium hydrosulfite. Other suitable reducing agentsinclude hydrazines and formaldehyde sodiumsulfoxylate, known asRongalite.

The invention is further illustrated by the following examples in whichthe description includes (a) the production of an aqueous suspensioncontaining the finely dispersed dyestuff pigment, and (b) thepreparation of the spinning solution. It is to be understood that theexamples are illustrative only and are not intended to limit the scopeof the invention. Parts are parts by weight unless otherwise specified.

Example 1 (a) 33.9 parts of a diazotized amine (Fast Black Salt G, seeDyestuff Tables of Schultz, 7th printing, supplementary volume 1, page94) are dissolved in 1000 parts of hot water with the addition of 89parts of acetic acid and 1.4 parts of an emulsifying agent as anethoxylated oleyl alcohol with 10-20 moles ethyleneoxide. With verystrong stirring there is added a solution of 19 parts of m-nitranilideof 2.3oxynaphthoic acid and an equivalent quantity of caustic sodasolution in 2000 parts of water. An aqueous suspension of awater-insoluble dyestulf pigment is thus formed having a pH of 8.2.

(b) 3,120 parts of this suspension, which contains 52.9 parts of thedyestufi pigment, are added with constant stirring to 14,650 parts of acuprarnrnonium solution having a cellulose content of 12% by weight.After the solution has been well homogenized, 1,730 parts of water arefurther added to give a cellulose content of 9% by weight of thespinning solution. The spinning solution, which contains 3% of dyestuffpigments with reference to the cellulose content, is then spun byextrusion in the usual manner to form a plurality of internally dyedcontinuous filaments.

The internally dyed filaments are woven into a. fabric, and the fabricis then etched by means of sodium hydrosulfite. Various portions of thefabric are etched where the sodium hydrosulfite has decomposedthedyestulf pig ment. The fabric is also ultra-fast dyed, having apermanent, solid coloring.

Example 2 (a) 50.3 parts of a diazotized amine (Fast Gold Orange SaltGR, see Dyestuif Tables ofSchultz, 7th printing, supplementary volume 2,page 178) are dissolved in 1000 parts of hot water with the addition of16.2 parts of acetic acid and 1.5 parts by weight of a suitableemulsifier as iso-dodecylphenol with 6 moles ethyleneoxide. To thisthere is added "together with intensive stirring a solution consistingof 16.3 parts of the o-toluidide of 2.3-oxynaphthoic acid in 2000'partsof water and an equivalent amount of caustic soda solution. The pH isset at 8.2 to 8.3 in the resulting suspension.

(1)) 1,500 parts of the dyestuif suspension thus pre pared, whichcontains 33.3 parts of the dyestufi pigment, are added with constantstirring to 9,250 parts of a viscose spinning solution which contains 9%by weight of cellulose. After the dyestufi pigments are evenlydistributed, 3,150 parts of water are further added so that a solutionready for spinning is provided having a content of 6% by weight ofcellulose. The concentration of the dyestuif pigment amounts to 4% byweight with reference to the cellulose.

From the internally dyed spun filaments, a textile fabric is producedwhich can be etched by means of sodium hydrosulfite.

Example 3 (a) 10 parts of Celliton Fast Yellow G (see Dyestuif Tables ofSchultz, 7th printing, volume 2, page 45) are dissolved in 85 parts of96% alcohol as the solution is warmed. The initial dye solution isintroduced drop by drop into 1000 parts of water being vigorouslystirred, the water containing 0.1% of an emulsifier, as in Example 2,Lavagent. A finely dispersed dyestuif suspension results. The alcohol isvaporized and the suspension is set at a pH value of 8.2.

(b) 3,120 parts of this suspension are added to 14,650 parts of acuprammonium spinning solution which has a cellulose content of 12% byweight. The remainder of the process is carried out in accordance withthe procedure described in Example 1(b) to obtain a fabric etched bysodium hydrosulfite.

Example 4 such a quantity that the spinning solution will contain 3% ofdyestuif pigment with reference to the cellulose content.

The spinning process is accomplished in the usual manner. The internallydyed filaments are woven into a fabric,

which is then etched by means of sodium hydrosulfite.

Example 5 (a) An aqueous suspension of a water-insoluble dyestutfpigment is produced in the same manner as Example 2 except that thefollowing dyestuff pigments were employed:

Oil Vermillon (Schultz No. 149) Pigment Fast (Schultz No. P olarorange Rcone. (Schultz No. 367) etching process will be accomplished in severalsteps one gets different color shades also with clear contours,

The invention is hereby claimed as follows:

1. A process for the production of an etched textile material containingsynthetic cellulose fibers which comprises dispersing a very finelydivided, water-insoluble organic dyestufi in a cellulosic spinningsolution, said dyestuff being capable of being decomposed by a reducingagent, spinning internally dyed synthetic cellulose fibers from saidspinning solution, and etching a textile material containing saidinternally dyed fibers by reaction with a reducing agent.

2. A process as defined in claim 1 wherein the dyestufi .is an azoicdyestuif.

3. A process as defined in claim 1 wherein the dyestufi" has a particlesize of not more than five microns.

4. A process as defined in claim 1 wherein the dispersion of thedyestufi is accomplished in the presence of an emulsifying agent.

5. A process for the production of an etched textile material containingsynthetic cellulose fibers which comprises dispersing a very finelydivided, water-insoluble organic dyestuff in the presence of anemulsifying agent in a cellulosic spinning solution such that thequantity of said dyestuif is from about 1% to 5% by weight of thecellulose content of said spinning solution, said dyestuff being capableof being decomposed by a reducing agent, spinning internally dyedsynthetic cellulose fibers from said spinning solution, and etching atextile material containing said internally dyed fibers by reaction witha reducing agent.

6. A process for the production of an etched textile material containingsynthetic cellulose fibers which comprises dispersing a very finelydivided, water-insoluble organic dyestuff in the presence of anemulsifying agent in a cellulosic spinning solution such that thequantity of said dyestufi is from about 2% to 4% by weight of thecellulose content of said spinning solution, said dyestuif being capableof being decomposed by a reducing agent, spinning internally dyedsynthetic cellulose fibers from said spinning solution, and etching atextile material containing said internally dyed fibers by reaction witha strong reducing agent.

7. A process as defined in claim 6 wherein the reducing agent is sodiumhydrosulfite.

8. A process as defined in claim 6 wherein the reducing agent ishydrazine.

9. A process as defined in claim 6 wherein the reducing agent isformaldehyde sodiumsulfoxylate.

10. A process of producing color-fast etched designs on a textilematerial containing synthetic cellulose fibers which comprises applyinga reducing agent to selected portions of said textile material in whichthe cellulose fibers have been uniformly colored by dispersing a finelydivided, water-insoluble organic dyestufi in an aqueous cellulosicspinning solution prior to spinning said fibers, said dyestufi beingcapable of being decomposed by said reducing agent.

11. A process as defined in claim 10 wherein the dyestutf is an azoicdyestuft.

References Cited in the file of this patent UNITED STATES PATENTS2,143,883 Kline et a1 Jan. 17, 1939 2,166,741 Karplus July 18, 19392,210,774 Pern'n et a1. Aug. 6, 1940 2,261,295 Schlack Nov. 4, 19412,345,345 Koch Mar. 28, 1944 2,385,885 Seymour et a1. Oct. 2, 19452,457,808 Dort Jan. 4, 1949 2,583,192 Waite Jan. 22, 1952 2,650,168 VanDijk Aug. 25, 1953

1. A PROCESS FOR THE PRODUCTION OF AN ETCHED TEXTILE MATERIAL CONTAININGSYNTHETIC CELLULOSE FIBERS WHICH COMPRISES DISPERSING A VERY FINELYDIVIDED, WATER-INSOLUBLE ORGANIC DYESTUFF IN A CELLULOSIC SPINNINGSOLUTION, SAID DYESTUFF BEING CAPABLE OF BEING DECOMPOSED BY A REDUCINGAGENT, SPINNING INTERNALLY DYED SYNTHETIC CELLULOSE FIBERS FROM SAIDSPINNING SOLUTION, AND ETCHING A TEXTILE MATERIAL CONTAINING SAIDINTERNALLY DYED FIBERS BY REACTION WITH A REDUCING AGENT.